Field of the Invention
The present invention relates to golf balls.
Specifically, the present invention relates to improvement of flight performance of golf balls.
Description of the Related Art
Golf balls have a large number of dimples on the surfaces thereof. The dimples disturb the air flow around the golf ball during flight to cause turbulent flow separation. This phenomenon is referred to as “turbulization”. Due to the turbulization, separation points of the air from the golf ball shift backwards leading to a reduction of drag. The turbulization promotes the displacement between the separation point on the upper side and the separation point on the lower side of the golf ball, which results from the backspin, thereby enhancing the lift force that acts upon the golf ball. Excellent dimples efficiently disturb the air flow. The excellent dimples produce a long flight distance.
There have been various proposals for dimples. US2009/0191982 (JP2009-172192) discloses a golf ball that has randomly arranged dimples. The dimple pattern of the golf ball is referred to as a random pattern. The random pattern can contribute to flight performance of the golf ball. US2012/0004053 (JP2012-10822) also discloses a golf ball having a random pattern.
US2007/0149321 (JP2007-175267) discloses a dimple pattern in which the number of units present in a high-latitude region is different from the number of units present in a low-latitude region. US2007/0173354 (JP2007-195591) discloses a dimple pattern in which the number of types of dimples present in a low-latitude region is greater than the number of types of dimples present in a high-latitude region. US2013/0196791 (JP2013-153966) discloses a dimple pattern in which the density of dimples is high and variations in sizes of dimples are small.
The greatest interest to golf players concerning golf balls is flight performance. Golf players desire golf balls having excellent flight performance. In light of flight performance, there is room for improvement in a dimple pattern.
An object of the present invention is to provide a golf ball having excellent flight performance.